The transportation industry widely uses signaling lamps to provide autos, truck and pull-behind vehicles and other vehicle extensions with the ability to signal to other vehicles. Ordinarily, these lamps must perform the functions of a tail light, turn signal and stop light with the use of a flasher switch in a given situation. The term signaling lamp is used herein to refer to lamps capable of performing any or all of these functions. State and federal laws typically require signaling lamps in an effort to ensure safe driving on roadways. One reason for the concern for safety is drivers in auto and trucks forget that their turn signal is on and or can't hear it (or don't see it flashing on their dash panel). Also, large trucks with very large trailers often have significant blind spots which can present a hazard to other motorists. For example, when a truck driver desires to change lanes, the driver can do no more than pay close attention to the side mirrors and properly use the vehicle turn signal. The turn signal triggers a signaling lamp flasher which generates intermittent contact between the vehicle power source and the signaling lamp to create a flashing light. An inattentive motorist, however, can easily be caught by surprise in this scenario--especially if the truck driver or automotive driver forgets to cancel the turn signal, or the turn signal fails to cancel by itself (and if the motorist fails to see the flashing lights). In fact, many accidents are caused each year by motorists momentarily taking their eyes off of the vehicle in front of them. There is therefore a substantial need to provide signaling lamps for automotive and large trucks and tractor trailers with the ability to better obtain the attention of the operating driver of the auto or truck.
Another important consideration to note is that it would also be very beneficial to alert the truck driver that the signaling lamp is operating properly or that the lamps are flashing. For example, if a signaling lamp fails due to a current overload, the truck driver will often have no knowledge of the failed signaling lamp and will therefore continue to operate the vehicle as if nothing is wrong. Typically, the driver will remain unaware of the problem until he receives a ticket or another driver notifies him.
As alluded to above, signaling lamps are also prone to current overloads, and they therefore rely heavily upon the fuse protection provided by the vehicle. This protection, however, is often not effective because the fuse will typically be responsible for protecting other devices throughout the vehicle as well. The result is that local current surges will still cause damage to the signaling lamp and its components. Providing an easily serviceable circuit protection device which is local to the lamp would also aid repair personnel in troubleshooting wiring problems. It is therefore desirable to provide signaling lamps with dedicated current overload protection to improve dependability and serviceability within the flasher unit.